In vivo liposome-mediated transfection of HLA-DR alpha-chain gene into pig hearts.
Scarcity of suitable donor organs remains a major problem for organ transplantation. Transfer of recipient HLA-genes into animal donor-organs during harvest could induce graft-tolerance without suppressing the recipient immune system.


OBJECTIVE
This pilot study aimed to test the feasibility of an in vivo gene transfer into pig hearts by intracoronary infusion of DNA:liposome-complexes and to detect the gene product by immunohistochemistry.


METHODS
The pcDV1-pL2-vector, containing the basesequence for HLA-DR alpha-chain in plasmids (1.3 kb) was selected. The plasmids were isolated with ethidiumbromide and incubated with lipofectin in a 1:3-ratio for 10 min. The DNA:lipofectin-complex was diluted to 10 cc with physiologic saline and delivered into the left anterior descending artery of 6 farm pigs over 10 min. As a control within the same animal, the same amount of lipofectin alone was infused into the first diagonal branch. Three pigs were sacrificed after 24 h, the other 3 after 48 h. Delivery of DNA:liposome-complexes was detected by oil red 0 staining, expression of HLA-DR alpha-chain-antigen with a monoclonal anti-HLA-DR alpha-antibody.


RESULTS
Transfection of the HLA-class-II DR-alpha-chain occurred in endothelial cells. Infiltrating cells around capillaries stained positively for HLA-DR-alpha. These infiltrating cells were negative for the pan B- and the pan T-cell-marker L26 and UCHL-1. There was no transfection and hypercellularity in the myocardium around the first diagonal branch.


CONCLUSIONS
In vivo intracoronary infusion of the HLA-DR alpha-chain-DNA:lipofectin-complex leads to expression of the corresponding antigen on pig endothelium for 48 h. The infiltrating cells require further characterization.
Aleksic
I
I
Department of Thoracic and Cardiovascular Surgery, Georg August University, Göttingen, Germany.
Ren
M
M
Popov
A
A
Freimark
D
D
Blanche
C
C
Czer
L
L
Trento
A
A
Barath
P
P
D000818:Animals; D006684:HLA-DR Antigens / Q000235:genetics*; D007150:Immunohistochemistry; D009206:Myocardium / Q000276:immunology*; D010714:Phosphatidylethanolamines / Q000008:administration & dosage*; D010865:Pilot Projects; D010957:Plasmids; D013552:Swine; D014162:Transfection / Q000379:methods*
D006684:HLA-DR Antigens; D010714:Phosphatidylethanolamines; C020888:1,2-dielaidoylphosphatidylethanolamine